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Biomedical subjects

N F Jacobs

Publications and source records attributed to N F Jacobs.

24 records · Page 2Linked to original sources
PubMed1975

Use of immunoglobulin coupled to agarose beads for examining the specificity of conjugates.

Preparations of purified immunoglobulins, light chains, and unrelated proteins (used as controls) were covalently linked to agarose beads and used to study the specificity of fluorescein isothiocyanate conjugates. The data demonstrate how these beads can be used to detect immunological and non-immunological reactivity in conjugates. Commercial conjugates, conjugates prepared in this laboratory, and fluorescein-labeled normal immunoglobulins demonstrated high reactivity with control beads unless chromatographed on diethylaminoethyl-cellulose to select for the proper fluorescein-protein ratio. Undesirable immunological reactivity could be demonstrated in commercial conjugates and was shown to be due to anti-light-chain antibody.

Antibody Specificity↗
PubMedDate not supplied

Serologic testing for gonorrhea.

A simple, adequately evaluated serologic test is not now available for use in gonorrhea screening programs. Some of the factors responsible for the relatively low sensitivity and specificity of serologic tests for gonorrhea as compared to cultural techniques are discussed. These include the time required for development of an immunologic response after infection, cross-reactivity with other antigens, and the persistence of antibody after therapy. At present, gonococcal serologic tests may be useful to the clinician in establishing the diagnosis of disseminated gonococcal infection, especially if paired sera demonstrate a change in antibody titer. Current research on the antigenic structure of the gonococcus may lead to the development of improved serologic tests for use in screening programs. However, the performance of any test may vary according to sex of the patient, presence of symptoms, history of prior gonococcal infection, and duration of the current infection. The physician must understand these factors when considering the use of any serologic test for gonorrhea.

False Positive Reactions↗
PubMedDate not supplied

Auxotypes and antibiotic susceptibility patterns of Neisseria gonorrhoeae from disseminated and local infections.

The arginine-hypoxanthine-uracil auxotype has been linked with the propensity of gonococci to cause disseminated infections. Gonococci recovered from 25 patients with disseminated gonococcal infections were compared with gonococci recovered from matched controls, patients with uncomplicated gonorrhea selected during the same month. Minimal inhibitory concentrations of penicillin, tetracycline, erythromycin, and ampicillin, and the nutritional requirements (auxotypes) for proline alone, arginine alone, arginine, hypoxanthine and uracil together, serine alone and cysteine-cystine (wild type) were analyzed by discriminant analysis. Significant susceptibility to penicillin characterized strains causing disseminated infection, and a proline requirement was the most common auxotype (48%) among strains isolated in Atlanta. Together the minimal inhibitory concentration of penicillin and the proline auxotype best separated the strains causing gonorrhea. The arginine-hypoxanthine-uracil auxotype was was found in only 24% of strains causing disseminated infections. A trait other than auxotype must determine the capacity of the organisms to disseminate.

Adult↗
PubMedDate not supplied

Experimental infection of the chimpanzee urethra and pharynx with Chlamydia trachomatis.

An isolate of Chlamydia trachomatis obtained from a man with nongonococcal urethritis was used to produce experimental urethral and pharyngeal infections in chimpanzees. After urethral inoculation of 8 X 10(1) inclusion-forming units (IFU), infections were established in three of three animals; urethral discharges developed in two. The infections persisted for five to nine weeks. Larger inocular (7 X 10(2) and 1 X 10(5) IFU) produced pharyngeal infections in two animals. The third animal's pharynx was not infected by 1 X 10(5) IFU. Chlamydial complement-fixing antibodies increased significantly in sera of two of three animals. This study provides an animal model for study of mucosal infection by C. trachomatis. The relative resistance of the chimpanzee pharynx to infection parallels clinical observations in man.

Animals↗